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Wpływ dodatków na właściwości reologiczne i proces sedymentacji atramentów ceramicznych, przeznaczonych do druku cyfrowego

Antosik Agnieszka

Szkło i Ceramika

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2019

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R. 70, nr 5

19--23

PL

W artykule przedstawiono wyniki badań dotyczących wpływu wybranych dodatków organicznych na właściwości reologiczne i proces sedymentacji zawiesin ceramicznych, przeznaczonych do druku cyfrowego. Jako bazę zastosowano czarny pigment o składzie pierwiastkowym Co-Ni-Fe-Cr, zawieszony w oleju napędowym, przy czym zawartość pigmentu wynosiła 30% wag. W ramach badań przetestowano dwa komercyjnie dostępne dodatki o właściwościach stabilizujących i zwilżających powierzchnię pigmentu w zawiesinie. Za każdym razem ilość dodatku w stosunku do pigmentu wynosiła od 0 do 5% wag. Wyniki przeprowadzonych badań wykazały, że zastosowanie odpowiednich dodatków organicznych wpływa korzystnie na dyspergowanie cząstek pigmentu w zawiesinie oraz zmianę właściwości reologicznych płynu, co ma bezpośredni wpływ na poprawę stabilności zawiesin ceramicznych w czasie. Najlepsze rezultaty otrzymano dla atramentów z dodatkiem 2 i 5% wag. środka BYKJET 9142 oraz 5% wag. środka ANTI-TERRA-U 100.

EN

The paper presents results concerning influence of selected organic additives on the rheological properties and sedimentation process of ceramic suspensions dedicated to ink jet printing decoration of ceramic tiles. As a solid phase the black Co-Ni-Fe-Cr pigment suspended in the diesel oil was used. The pigment content was 30 wt%. In research 2 commercially available additives with wetting and dispersing properties of oilborne fluid where tested. In all cases the content of additive was from 0 to 5 wt% in respect to solid phase. It was shown that application of appropriate organic additives lead to the dispersion of pigment particles in the suspension and the change in rheological properties of the fluid, and in so doing improving of stability of ceramic suspension over time. The best results were obtained for suspensions with 2 and 5 wt% of BYKJET 9142 and 5 wt% of ANTI-TERRA-U 100.

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The Influence of Steric Stabilization on Process of Au, Pt Nanoparticles Formation

Luty-Błocho M.

Archives of Metallurgy and Materials

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2019

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Vol. 64, iss. 1

55--63

EN

Nanoparticles are very fascinating area of science not only due to their unique properties but also possibility of producing new more complex materials, which may find an application in modern chemistry, engineering and medicine. In process of nanoparticles formation very important aspect is a rate of individual stage i.e. reduction, nucleation and autocatalytic growth, because this knowledge allows for proper materials design, morphology manipulation, stability. The last one aspect can be realized using proper electrostatic, steric and electrosteric stabilization. However until now nobody reports and measures kinetic rates of all stages during process of particles formation in the presence of steric stabilizers. Thus, the main contribution of this paper is determination of individual rate constants for nanoparticles formation in the presence of steric stabilizers and their comparison to the system without stabilizer. For this purpose, an aqueous solution of Au(III) and Pt(IV) ions were mixed with steric stabilizers like PVA and PVP, and reduced using L-ascorbic acid as a mild and sodium borohydride as a strong reductant. As a results stable nanoparticles were formed and process of their formation was registered spectrophotometrically. From obtained kinetic curves the values of observed rate constants for reduction metal ions, slow nucleation and fast autocatalytic growth were determined using Watzky-Finke model. It was found that the addition of polymer affects the rate of the individual stages. The addition of steric stabilizers to gold ions reduced with L-ascorbic acid causes that the process of nucleation and autocatalytic growth slows down and the value of observed rate constants for nucleation changes from 3.79·10-3 (without polymer) to 7.15·10-5 s-1 (with PVA) and for growth changes from 1.15·103 (without polymer) to 0.48·102 s-1 M-1 (with PVA). However, the rate of the reduction reaction of Au(III) ions is practically unchanged. In case of using strong reductant the addition of polymer effects on the shape of kinetic curve for reduction of Au(III) and it suggests that mechanism is changed. In case of Pt(IV) ions reduction with L-ascorbic acid, the process speeds up a little when PVA was added. Determined values of observed rate constants for nucleation and growth platinum nanoparticles decrease twice comparing to the system without polymer. The reduction of Pt(IV) ions with sodium borohydride accelerates when PVP was added and slows down when PVA was used. Moreover, the size of obtained colloidal gold and platinum was also analysed using DLS method. Obtained results (rate constants) may be useful in the process of nanomaterials synthesis, in particular in microflow.

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Influence of polyvinylpyrrolidone adsorption on stability of silica aqueous suspension - effects of polymer concentration and solid content

Perez Huertas S., Terpiłowski K., Wiśniewska M., Zarko V.

Physicochemical Problems of Mineral Processing

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2017

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Vol. 53, iss. 1

121--135

EN

The influence of polyvinylpyrrolidone (PVP) adsorption on the silica suspension stability was studied. The effects of silica content, polymer addition and suspension dilution with water were examined. The turbidimetry method was applied to examine stability of the investigated systems as a function of time. It was shown that the suspension without polymer was characterized by the smallest stability, whereas the systems containing PVP (before and after dilution) are successively stable. The specific conformation of PVP chains on the solid surface is responsible for the stabilization–flocculation properties of PVP in the colloidal suspension.

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The Synthesis of Stable Platinum Nanoparticles in the Microreactor

Luty-Błocho M., Wojnicki M., Grzonka J., Kurzydłowski K.J.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 2

509--512

EN

In this work, the synthesis of the spherical clusters containing 3-4 nm platinum nanoparticles enclosed in a polymer capsule is described. The process of nanoparticles formation was intensified by using a microreactor. The application of microreactor enabled us to shorten the time of redox reaction and nucleation stage up to 6 seconds at 105°C in comparison with the process carried out in a batch reactor at 40°C. Using Vitamin C as a bio-reducer of platinum(IV) complexes and biocompatible polymers, the products non-toxic and environmentally friendly, stable for at least 9 months, were obtained. Presented procedure for nanoparticles synthesis seems to be an alternative method for platinum recovery from solutions containing platinum(IV) chloride complexions.

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W pracy, przedstawiono syntezę sferycznych klastrów zawierających 3-4 nm nanocząstki platyny zamknięte w polimerowej otoczce. Proces formowania nanocząstek platyny został zintensyfikowany poprzez użycie mikroreaktora. Użycie mikroreaktora skróciło czas reakcji redukcji oraz etapu zarodkowania do 6 s w temperaturze 105°C w porównaniu do procesu przeprowadzonego w reaktorze okresowym w temperaturze 40°C. Użycie witaminy C jako bioreduktora chlorkowych kompleksów platyny(lV) oraz biokompatybilnego polimeru pozwala na uzyskanie nietoksycznych oraz stabilnych przez co najmniej 9 miesięcy produktów. Przedstawiona metoda syntezy nanocząstek może stanowić alternatywny sposób odzysku platyny z roztworów zawierających jej chlorkowy kompleks.